Initially a Calvinist, he became a prominent and influential Arminian teaching at the Academy of Sedan. He was an open critic of the Synod of Dort of 1618-1619. Coming to France around 1590, he was naturalised by Henry IV. Lord Herbert of Cherbury, who gave Tilenus his De Veritate, took his original name to be Tieleners.
A divisive controversy with Pierre Du Moulin broke out in 1612.
The issue was patched up by 1615. In April 1620 Tilenus set up, at L"Isle, near Orléans, a debate with John Cameron, on the conclusions at Dort.
Cameron published his version as Amica collatio de gratia et voluntatis humanae concursu in vocatione (1622). Later in 1620 Tilenus was finally forced out from Sedan by general hostility.
He was also close to the philosopher Walter Donaldson. in Paraenesis ad Scotos Genevensis disciplinae zelotas.
David Calderwood in his Altare Damascenum (1623) attacked Tilenus. Gisbertus Voetius also attacked Tilenus, and was noted by Grotius.
He was on friendly terms with Hugo Grotius. They shared a house in 1622/3 in the Rue de Condé, Paris.