You can find a YouTube playlist here with many of the songs suggested below.
Gathering
The psalm is a wonderful invitation to sing together in praise and there are many songs, and indeed other psalms, which pick up the themes in it. The first verse could suggest well known songs such as Come, children, join and sing (CH 185) or Come people of the risen King (MP 1267 / CCLI / Getty), while Let’s sing unto the Lord a hymn of glad rejoicing (CH 176) would be great if your congregation know it. Let all creation sing (Resound) would also pick up on the idea of “all the earth” singing to God, as would All creatures of our God and King (CH 147 / MP 7) and My Jesus, my Saviour / Shout to the Lord (CH 531 / MP 1003 / CCLI). Alternatively if you wanted to focus on the verses about God’s steadfast love and faithfulness then you could use Forever (MP 1046 / CCLI) or Great is thy faithfulness (CH 153 / MP 200).
As suggested throughout the Easter season, if you used any of the more contemporary hymns on Easter Sunday such as Christ is alive, and the universe must celebrate (CH 422), Away with gloom, away with doubt (CH 418), Earth, earth, awake; your praises sing (CH 420) or Christ was raised (Resound) it could also be worth repeating them to help them become part of your congregation’s repertoire.
Word
While it may seem an odd time of year to sing it, Joy to the world (CH 320 / MP 393) is probably the best known song inspired by Psalm 98. When you look at the lyrics though it is just as appropriate for the Sunday before Ascension Day as for Christmas. There are also a couple of contemporary versions of this with added choruses from Chris Tomlin (CCLI) and Hillsong (CCLI). From life's beginning (Resound) would work really well for bands with an anthemic feel to it. Let’s sing to the Lord (CH 126) is set to a Brazilian folk melody and is well known in ecumenical circles, you could have lots of fun getting a Latin American feel with this. Interestingly this psalm seems to have inspired quite a few settings in 6/8 time and Sing a new song to the Lord (CH 62) and Sing to the Lord a new song (Grace) are probably the best options for congregations accompanied by organ.
Response
The themes in the Gospel and the Epistle both repeat a lot of what we have seen in the readings in the last few weeks. The commandment to love one another is picked up explicitly in A new commandment (MP 1), This is my will, my new command (CH 357) and Love one another (WGRG). Love is the touch of intangible joy (CH 115) or I will sing a song of love (WGRG) would explore different aspects of love and you could also consider some short songs such as Ubi caritas (CH 801), Jesu, Jesu, fill us with your love (Hope) and He came down that we may have love (CH 359). Finally, we have the promise that if we keep this commandment we will abide in Jesus’ love and Abide (CCLI) by Aaron Williams and Abide (CCLI) by Housefires would both pick this up.
The passage from Acts looks at the inclusion of all believers as it did last week and this could link to songs such as Let us build a house where love can dwell (CH 198) (omitting v3 if not celebrating communion) or the lively Draw the circle wide (MV 145 / link). We also have the image of the Holy Spirit falling on those who heard the word and we could respond to that with Spirit of the living God (CH 619 / MP 613) or Spirit fall (CCLI). Another angle would be songs about baptism and We know that Christ is raised and dies no more (CH 635) and Now through the grace of God we claim (CH 637) and would both be good songs for exploring this in the Easter season.
Sending
God’s love and our call to love one another is also a natural place to end with songs such as We sing a love that sets all people free (CH 622), Build my life (CCLI), Build your kingdom here (CCLI) and God loved the world so much (WGRG recording and lyrics). Some more general options around the theme of God’s love could be Love came down (MP 1237 / CCLI), Through the love of God, our Saviour (CH 562), and Here is love vast as the ocean (MP 987 / Hymnary / CCLI) which can be sung either as a Victorian hymn or in the worship song version by Matt Redman.